diff --git a/gradle.properties b/gradle.properties
index ecbd984d..40646970 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -5,7 +5,7 @@
 version=0.23.0-SNAPSHOT
 group=org.jetbrains.kotlinx
 
-kotlin_version=1.9.20
+kotlin_version=1.9.21
 
 asm_version=9.3
 slf4j_version=1.8.0-alpha2